US4869574A - Hybrid optical correlator - Google Patents
Hybrid optical correlator Download PDFInfo
- Publication number
- US4869574A US4869574A US07/204,153 US20415388A US4869574A US 4869574 A US4869574 A US 4869574A US 20415388 A US20415388 A US 20415388A US 4869574 A US4869574 A US 4869574A
- Authority
- US
- United States
- Prior art keywords
- image
- matched filter
- orientation
- light
- detector
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
- G02B27/46—Systems using spatial filters
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06E—OPTICAL COMPUTING DEVICES; COMPUTING DEVICES USING OTHER RADIATIONS WITH SIMILAR PROPERTIES
- G06E3/00—Devices not provided for in group G06E1/00, e.g. for processing analogue or hybrid data
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/88—Image or video recognition using optical means, e.g. reference filters, holographic masks, frequency domain filters or spatial domain filters
Definitions
- This matched filter technique has the disadvantage that it does not compensate for changes of scale or rotation of the object. Typically, a ten percent change of these parameters is enough to destroy the correlation.
- Another technique known as Fourier plane detection, is taught by Nicholas George. The image of the object is Fourier transformed as above, but a detector array, rather than a holographic matched filter, is placed in the Fourier plane. George teaches a specially shaped detector, composed of annular ring elements in one half of the detector plane, and wedge elements in the other half. This detector is illustrated in FIG. 1 of the drawing and is disclosed in U.S. Pat. No. 3,689,772, which issued on Sept.
- the detector is especially suited to Fourier plane detection, as the center symmetry means that the same element of information will fall on a ring or on a wedge structure of the detector.
- the ring structure then indicates the spatial frequency of a feature of information and the wedge structure indicates the angular direction of that feature.
- the ring, wedge information is placed into a digital computer, and any of a variety of algorithms are used to attempt to classify (recognize) the object being detected.
- This Fourier plane detection technique has the disadvantage that it does not determine object location. It determines if a desired object is in the field of view, but cannot determine where it is in the field of view. It has the disadvantage that multiple images in the field of view will not necessarily result in multiple determinations. It also has the disadvantage that unwanted information in the field of view such as cutter is superimposed on the desired information so that the system is not highly robust to clutter.
- Another object of this invention is to provide a hybrid optical correlator which is a hybrid of the matched filter technique and the Fourier plane detection technique.
- Another object of this invention is to provide a hybrid optical correlator which takes advantage of the strengths of both a matched filter correlation technique and the Fourier plane detection technique and uses these strengths to counterbalance the weaknesses of each of the other techniques.
- a hybrid optical correlator uses the benefit of a Fourier plane detector to adjust the image of an object so that a optical matched filter can provide a correlation independent of scale and orientation of the object. This is accomplished by utilizing the matched filter technique and the Fourier plane detection technique and taking the advantages and strengths of each and utilizing the strengths of each to counterbalance the weakness of the other to provide the desired optical correlation independent of scale and orientation of the object.
- FIG. 1 is a diagram of a Fourier plane detector utilized in this invention.
- FIG. 2 is a schematic illustration of a hybrid optical correlator in accordance with this invention.
- the hybrid optical correlator includes a laser 10 which illuminates lens 12 and the output from lens 12 falls on object modulator 14.
- Light from object 16 is transmitted through image adjusting subsystem 18 and onto object modulator 14.
- the output of the object from object modulator 14 in laser light is Fourier transformed by lens 20 and then a portion of the output from lens 20 is transmitted through beamsplitter 22 onto holographic matched filter 24.
- Lens 26 is used to retransform diffracted light from matched filter 24 and project it onto correlation plane 28 which is usually a video camera.
- the above description is the same as that for a Vander Lugt correlator except for the image adjusting subsystem 18 set forth above.
- Fourier plane detector 30 is a Fourier plane detector of the type taught by Nicholas George in U.S. Pat. No.: 3,689,772 which issued on Sept. 5, 1972.
- Fourier plane detector 30 has a multiplicity of wedge detectors 33 and a multiplicity of concentric annular detectors 31 that are utilized to determine the size and orientation of the object being displayed on the modulator.
- the output of Fourier plane detector 30 is connected by cable 32 to signal processor 34 such as a small digital computer.
- image adjusting subsystem 18 can consist of image rotators such as dove prisms or mirrors or image scaling optics such as zoom lenses that are used to adjust the size of the object image as well as the orientation of the object image. If desired, image adjusting subsystem 18 can consist of electronics to rotate or change scale on the image such as by being on a cathode ray tube, if video imagery is used as the input. It is also understood that the output from signal processor 34 can be used to adjust other means in the system to adjust the size and the orientation of the object to make it coincide with that on holographic matched filter 24.
- Fourier plane detector 30 will have signals in a set of rings 31 associated with the size of the rectangle and signals in a set of wedges 33 associated with the orientation of the rectangle.
- the signals produced from rings 31 are used to send signals to signal processor 34 that produces signals for driving image adjusting subsystem 18 to adjust the size of the object and signals from wedges 33 are used to drive image adjusting subsystem 18 through signal processor 34 to adjust orientation of the object to the predetermined angle correct for matched filter 24.
- the object and reference are in an identical position so that matched filter 24 will diffract and the diffracted light will be retransformed by lens 26 and fall onto correlation plane 28 to produce a correlator spot on correlation plane 28.
- the location of the correlation spot will disclose the location of the object rectangle in the field of view. That is, the location of the correlator spot on the screen of the video camera will enable one to visually see the location of the object rectangle in the field of view.
- matched filter 24 is a powerful enough discriminator that it will correlate only when the object/reference pair are matched.
- Fourier plane detector 30 does not directly associate the short vs. longside with the orientations of the two sides. Two rectangles rotated 90 degrees apart have the same first order binary Fourier plane signal. It is possible to do a more sophisticated analysis of the Fourier plane signal to remove the ambiguity, but it may not be necessary. If the object doesn't match the target, it makes no difference. If the object does match, then the system can try both rotational positions. Dividing the rings into two sections is enough to remove the ambiguity for this class of objects.
Abstract
A hybrid optical correlator which uses a Fourier plane detector to cause adjustment of an image of an object in scale and orientation so that a matched filter can provide a correlation of the object independent of scale and orientation.
Description
The invention described herein may be manufactured, used, or licensed by or for the Government for governmental purposes without the payment to me of any royalties thereon.
In the past, a technique of image correlation by means of a lens has been used in which a two-dimensional Fourier transform of the image of an object is used to illuminate a hologram of the Fourier transform of a reference, and retransforming the result with another lens to get the correlation between the object and the reference is taught by A. Vander Lugt and this device is known as an optical matched filter. This technique is probably the mathematical optimum way of comparing an object to a reference. It has the special property of spatial invariance, and correlation occurs regardless of where the object is in the field of view. The location of the spot of light in the correlation plane describes the location of the object. This technique is robust against many forms of object clutter and provides multiple independent correlation spots if there are multiple images in the field of view. This matched filter technique has the disadvantage that it does not compensate for changes of scale or rotation of the object. Typically, a ten percent change of these parameters is enough to destroy the correlation. Another technique, known as Fourier plane detection, is taught by Nicholas George. The image of the object is Fourier transformed as above, but a detector array, rather than a holographic matched filter, is placed in the Fourier plane. George teaches a specially shaped detector, composed of annular ring elements in one half of the detector plane, and wedge elements in the other half. This detector is illustrated in FIG. 1 of the drawing and is disclosed in U.S. Pat. No. 3,689,772, which issued on Sept. 5, 1972.This detector is especially suited to Fourier plane detection, as the center symmetry means that the same element of information will fall on a ring or on a wedge structure of the detector. The ring structure then indicates the spatial frequency of a feature of information and the wedge structure indicates the angular direction of that feature. The ring, wedge information is placed into a digital computer, and any of a variety of algorithms are used to attempt to classify (recognize) the object being detected.
This Fourier plane detection technique has the disadvantage that it does not determine object location. It determines if a desired object is in the field of view, but cannot determine where it is in the field of view. It has the disadvantage that multiple images in the field of view will not necessarily result in multiple determinations. It also has the disadvantage that unwanted information in the field of view such as cutter is superimposed on the desired information so that the system is not highly robust to clutter.
Accordingly, it is an object of this invention to provide a hybrid optical correlator which uses a Fourier plane detector to adjust the image of an object so that a matched filter can provide a correlation, independent of scale and orientation of the object.
Another object of this invention is to provide a hybrid optical correlator which is a hybrid of the matched filter technique and the Fourier plane detection technique.
Another object of this invention is to provide a hybrid optical correlator which takes advantage of the strengths of both a matched filter correlation technique and the Fourier plane detection technique and uses these strengths to counterbalance the weaknesses of each of the other techniques.
Other objects and advantages of this invention will be obvious to those skilled in this art.
In accordance with this invention, a hybrid optical correlator is provided which uses the benefit of a Fourier plane detector to adjust the image of an object so that a optical matched filter can provide a correlation independent of scale and orientation of the object. This is accomplished by utilizing the matched filter technique and the Fourier plane detection technique and taking the advantages and strengths of each and utilizing the strengths of each to counterbalance the weakness of the other to provide the desired optical correlation independent of scale and orientation of the object.
FIG. 1 is a diagram of a Fourier plane detector utilized in this invention, and
FIG. 2 is a schematic illustration of a hybrid optical correlator in accordance with this invention.
Referring now to the drawing, the hybrid optical correlator includes a laser 10 which illuminates lens 12 and the output from lens 12 falls on object modulator 14. Light from object 16 is transmitted through image adjusting subsystem 18 and onto object modulator 14. The output of the object from object modulator 14 in laser light is Fourier transformed by lens 20 and then a portion of the output from lens 20 is transmitted through beamsplitter 22 onto holographic matched filter 24. Lens 26 is used to retransform diffracted light from matched filter 24 and project it onto correlation plane 28 which is usually a video camera. The above description is the same as that for a Vander Lugt correlator except for the image adjusting subsystem 18 set forth above. In the above description, diffracted light from holographic matched filter 24 will not result unless a correlation is made. A portion of the transformed light from lens 20 is also deflected by beamsplitter 22 and falls on detector 30 which is a Fourier plane detector of the type taught by Nicholas George in U.S. Pat. No.: 3,689,772 which issued on Sept. 5, 1972. As illustrated, Fourier plane detector 30 has a multiplicity of wedge detectors 33 and a multiplicity of concentric annular detectors 31 that are utilized to determine the size and orientation of the object being displayed on the modulator. The output of Fourier plane detector 30 is connected by cable 32 to signal processor 34 such as a small digital computer. The outputs provided by signal processor 34 from the outputs of detector 30 are then used through cable 36 to drive image adjusting subsystem 18 to adjust the size and orientation of the image being transmitted from image adjusting subsystem 18 to object modulator 14. Image adjusting subsystem 18 can consist of image rotators such as dove prisms or mirrors or image scaling optics such as zoom lenses that are used to adjust the size of the object image as well as the orientation of the object image. If desired, image adjusting subsystem 18 can consist of electronics to rotate or change scale on the image such as by being on a cathode ray tube, if video imagery is used as the input. It is also understood that the output from signal processor 34 can be used to adjust other means in the system to adjust the size and the orientation of the object to make it coincide with that on holographic matched filter 24.
In operation, when the object and the reference are similar rectangles but not necessarily to the same scale or orientation, there will be no output from matched filter 24 correlator. However, Fourier plane detector 30 will have signals in a set of rings 31 associated with the size of the rectangle and signals in a set of wedges 33 associated with the orientation of the rectangle. The signals produced from rings 31 are used to send signals to signal processor 34 that produces signals for driving image adjusting subsystem 18 to adjust the size of the object and signals from wedges 33 are used to drive image adjusting subsystem 18 through signal processor 34 to adjust orientation of the object to the predetermined angle correct for matched filter 24. With image adjusting subsystem 18 adjusted to the correct position, the object and reference are in an identical position so that matched filter 24 will diffract and the diffracted light will be retransformed by lens 26 and fall onto correlation plane 28 to produce a correlator spot on correlation plane 28. The location of the correlation spot will disclose the location of the object rectangle in the field of view. That is, the location of the correlator spot on the screen of the video camera will enable one to visually see the location of the object rectangle in the field of view.
Consider now a more detailed object such as an automobile. If the object and the reference are identical, there will be a strong correlation after image adjusting subsystem 18 is aligned. However, if the object automobile is different such as sedan rather than a station wagon, matched filter 24 is a powerful enough discriminator that it will correlate only when the object/reference pair are matched.
There is a possibility of ambiguity. Fourier plane detector 30 does not directly associate the short vs. longside with the orientations of the two sides. Two rectangles rotated 90 degrees apart have the same first order binary Fourier plane signal. It is possible to do a more sophisticated analysis of the Fourier plane signal to remove the ambiguity, but it may not be necessary. If the object doesn't match the target, it makes no difference. If the object does match, then the system can try both rotational positions. Dividing the rings into two sections is enough to remove the ambiguity for this class of objects.
Claims (6)
1. A hybrid optical correlator comprising object modulation means for producing an image of an object in collimated light, Fourier transform means mounted for receiving the image of said object in collimated light and transmitting an output to a holographic matched filter, splitter means between said Fourier transform means and said holographic matched filter for splitting off a portion of said output and onto detector means for detecting the transmitted size and orientation of the image, and means which responds to outputs from said detector means and adjusts the orientation and size of the image of the object being projected onto said object modulator means to cause said matched filter to correlate.
2. A hybrid optical correlator as set forth in claim 1, wherein said means which responds to said outputs includes a signal processor and an image adjusting subsystem, said signal processor processing outputs and producing signals which are utilized in said image adjusting subsystem for adjusting the size and orientation of the image.
3. A hybrid optical correlator as set forth in claim 2, wherein said detector means includes triangular detectors and semicircular ring detectors for detecting the size and orientation of the image.
4. A hybrid optical correlator as set forth in claim 3, wherein said object modulator is illuminated by laser light.
5. A hybrid optical correlator as set forth in claim 4, wherein a lens is mounted for retransforming diffracted light from said matched filter and for projecting said retransformed diffracted light onto a correlation plane.
6. A hybrid optical correlator comprising a laser for producing a laser beam, a lens for collimating the light from said laser, and an object modulator for receiving the collimated light from the lens and for receiving the image of an object from an imaging system that directs the image of the object to the object modulator, a Fourier transform lens mounted for receiving from the object modulator the image in laser light and for transmitting its output to a holographic matched filter, a beamsplitter mounted between said Fourier transform lens and said matched filter, a lens mounted for retransforming diffracted light from said matched filter and causing the retransformed light to fall onto a correlation plane, said beamsplitter adapted for splitting off a portion of the light from said Fourier transform lens and for projecting the split off light to a detector that has a multiplicity of wedges and a multiplicity of semicircular rings for detecting the orientation and size of the image of an object, said detector having outputs that are connected to a signal processor for processing signals produced at outputs of said detector, said signal processor producing signals from the outputs of said detector for providing adjusting signals, and said adjusting signals from said signal processor being connected to an image adjusting subsystem which transmits the image of the object to said object modulator, said image adjusting subsystem including means for adjusting the scale of the image of an object and the orientation of the image of an object to adjust the image to a predetermined size and orientation which is correct relative to said matched filter to cause said matched filter to correlate.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/204,153 US4869574A (en) | 1988-05-13 | 1988-05-13 | Hybrid optical correlator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/204,153 US4869574A (en) | 1988-05-13 | 1988-05-13 | Hybrid optical correlator |
Publications (1)
Publication Number | Publication Date |
---|---|
US4869574A true US4869574A (en) | 1989-09-26 |
Family
ID=22756844
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/204,153 Expired - Fee Related US4869574A (en) | 1988-05-13 | 1988-05-13 | Hybrid optical correlator |
Country Status (1)
Country | Link |
---|---|
US (1) | US4869574A (en) |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5002348A (en) * | 1989-05-24 | 1991-03-26 | E. I. Du Pont De Nemours And Company | Scanning beam optical signal processor |
EP0435829A2 (en) * | 1989-12-28 | 1991-07-03 | JENOPTIK GmbH | Arrangement for the analysis of thermal waves in layered systems |
US5040140A (en) * | 1989-04-28 | 1991-08-13 | The United States Of America As Represented By The Secretary Of The Air Force | Single SLM joint transform correaltors |
US5073006A (en) * | 1990-03-30 | 1991-12-17 | The United States Of America As Represented By The Secretary Of The Air Force | Compact 2f optical correlator |
US5111314A (en) * | 1990-08-09 | 1992-05-05 | Grumman Aerospace Corporation | Optical correlator interconnect for optical computer |
EP0587020A2 (en) * | 1992-08-31 | 1994-03-16 | Texas Instruments Incorporated | Real time optical correlation system |
US5381362A (en) * | 1993-07-30 | 1995-01-10 | Sri International | Reprogrammable matched optical filter and method of using same |
US6005985A (en) * | 1997-07-29 | 1999-12-21 | Lockheed Martin Corporation | Post-processing system for optical correlators |
US6016330A (en) * | 1996-10-18 | 2000-01-18 | International Business Machines Corporation | Encoding and detection of balanced codes |
US20030113020A1 (en) * | 2001-12-19 | 2003-06-19 | General Electric Company | Method for the extraction of image features caused by structure light using template information |
US20030152274A1 (en) * | 1998-12-31 | 2003-08-14 | Mcgrew Stephen P. | Method and apparatus for reading and verifying holograms |
US7095435B1 (en) | 2004-07-21 | 2006-08-22 | Hartman Richard L | Programmable multifunction electronic camera |
US20080152082A1 (en) * | 2006-08-16 | 2008-06-26 | Michel Bouchard | Method and apparatus for use in security screening providing incremental display of threat detection information and security system incorporating same |
US7734102B2 (en) | 2005-05-11 | 2010-06-08 | Optosecurity Inc. | Method and system for screening cargo containers |
US7899232B2 (en) | 2006-05-11 | 2011-03-01 | Optosecurity Inc. | Method and apparatus for providing threat image projection (TIP) in a luggage screening system, and luggage screening system implementing same |
US7991242B2 (en) | 2005-05-11 | 2011-08-02 | Optosecurity Inc. | Apparatus, method and system for screening receptacles and persons, having image distortion correction functionality |
US8494210B2 (en) | 2007-03-30 | 2013-07-23 | Optosecurity Inc. | User interface for use in security screening providing image enhancement capabilities and apparatus for implementing same |
US9632206B2 (en) | 2011-09-07 | 2017-04-25 | Rapiscan Systems, Inc. | X-ray inspection system that integrates manifest data with imaging/detection processing |
US10302807B2 (en) | 2016-02-22 | 2019-05-28 | Rapiscan Systems, Inc. | Systems and methods for detecting threats and contraband in cargo |
US11175791B1 (en) * | 2020-09-29 | 2021-11-16 | International Business Machines Corporation | Augmented reality system for control boundary modification |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3689772A (en) * | 1971-08-18 | 1972-09-05 | Litton Systems Inc | Photodetector light pattern detector |
US4715683A (en) * | 1986-11-10 | 1987-12-29 | The United States Of America As Represented By The Secretary Of The Army | Modified liquid crystal television as a spatial light modulator |
US4809340A (en) * | 1988-04-08 | 1989-02-28 | Battelle Memorial Institute | Optical correlation system |
-
1988
- 1988-05-13 US US07/204,153 patent/US4869574A/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3689772A (en) * | 1971-08-18 | 1972-09-05 | Litton Systems Inc | Photodetector light pattern detector |
US4715683A (en) * | 1986-11-10 | 1987-12-29 | The United States Of America As Represented By The Secretary Of The Army | Modified liquid crystal television as a spatial light modulator |
US4809340A (en) * | 1988-04-08 | 1989-02-28 | Battelle Memorial Institute | Optical correlation system |
Non-Patent Citations (6)
Title |
---|
"Automatic Pattern Recognition", by Nicholas George 1984, cover sheet and p. 35. |
"Hybrid optical-digital pattern recognition", Merkle et al, Applied Optics,ol. 23, #10, 15 May 1984. |
"Signal Detection By Complex Spatial Filtering", by A. Vander Lugt, IEEE Apr. 1964, pp. 139-145. |
Automatic Pattern Recognition , by Nicholas George 1984, cover sheet and p. 35. * |
Hybrid optical digital pattern recognition , Merkle et al, Applied Optics, vol. 23, 10, 15 May 1984. * |
Signal Detection By Complex Spatial Filtering , by A. Vander Lugt, IEEE Apr. 1964, pp. 139 145. * |
Cited By (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5040140A (en) * | 1989-04-28 | 1991-08-13 | The United States Of America As Represented By The Secretary Of The Air Force | Single SLM joint transform correaltors |
US5002348A (en) * | 1989-05-24 | 1991-03-26 | E. I. Du Pont De Nemours And Company | Scanning beam optical signal processor |
EP0435829A2 (en) * | 1989-12-28 | 1991-07-03 | JENOPTIK GmbH | Arrangement for the analysis of thermal waves in layered systems |
EP0435829A3 (en) * | 1989-12-28 | 1992-06-10 | Jenoptik Jena G.M.B.H. | Arrangement for the analysis of thermal waves in layered systems |
US5073006A (en) * | 1990-03-30 | 1991-12-17 | The United States Of America As Represented By The Secretary Of The Air Force | Compact 2f optical correlator |
US5111314A (en) * | 1990-08-09 | 1992-05-05 | Grumman Aerospace Corporation | Optical correlator interconnect for optical computer |
KR100372214B1 (en) * | 1992-08-31 | 2003-08-06 | 텍사스 인스트루먼츠 인코포레이티드 | Real-time Optical Correlation System |
EP0587020A3 (en) * | 1992-08-31 | 1994-08-24 | Texas Instruments Inc | Real time optical correlation system |
EP0587020A2 (en) * | 1992-08-31 | 1994-03-16 | Texas Instruments Incorporated | Real time optical correlation system |
US5381362A (en) * | 1993-07-30 | 1995-01-10 | Sri International | Reprogrammable matched optical filter and method of using same |
US6016330A (en) * | 1996-10-18 | 2000-01-18 | International Business Machines Corporation | Encoding and detection of balanced codes |
US6005985A (en) * | 1997-07-29 | 1999-12-21 | Lockheed Martin Corporation | Post-processing system for optical correlators |
US20030152274A1 (en) * | 1998-12-31 | 2003-08-14 | Mcgrew Stephen P. | Method and apparatus for reading and verifying holograms |
US6832003B2 (en) * | 1998-12-31 | 2004-12-14 | Mcgrew Stephen P. | Method and apparatus for reading and verifying holograms |
US20050100222A1 (en) * | 1998-12-31 | 2005-05-12 | Mcgrew Stephen P. | Method and apparatus for reading and verifying holograms |
US20030113020A1 (en) * | 2001-12-19 | 2003-06-19 | General Electric Company | Method for the extraction of image features caused by structure light using template information |
US7136171B2 (en) * | 2001-12-19 | 2006-11-14 | General Electric Company | Method for the extraction of image features caused by structure light using template information |
US7095435B1 (en) | 2004-07-21 | 2006-08-22 | Hartman Richard L | Programmable multifunction electronic camera |
US7734102B2 (en) | 2005-05-11 | 2010-06-08 | Optosecurity Inc. | Method and system for screening cargo containers |
US7991242B2 (en) | 2005-05-11 | 2011-08-02 | Optosecurity Inc. | Apparatus, method and system for screening receptacles and persons, having image distortion correction functionality |
US7899232B2 (en) | 2006-05-11 | 2011-03-01 | Optosecurity Inc. | Method and apparatus for providing threat image projection (TIP) in a luggage screening system, and luggage screening system implementing same |
US20080152082A1 (en) * | 2006-08-16 | 2008-06-26 | Michel Bouchard | Method and apparatus for use in security screening providing incremental display of threat detection information and security system incorporating same |
US8494210B2 (en) | 2007-03-30 | 2013-07-23 | Optosecurity Inc. | User interface for use in security screening providing image enhancement capabilities and apparatus for implementing same |
US10830920B2 (en) | 2011-09-07 | 2020-11-10 | Rapiscan Systems, Inc. | Distributed analysis X-ray inspection methods and systems |
US9632206B2 (en) | 2011-09-07 | 2017-04-25 | Rapiscan Systems, Inc. | X-ray inspection system that integrates manifest data with imaging/detection processing |
US10422919B2 (en) | 2011-09-07 | 2019-09-24 | Rapiscan Systems, Inc. | X-ray inspection system that integrates manifest data with imaging/detection processing |
US10509142B2 (en) | 2011-09-07 | 2019-12-17 | Rapiscan Systems, Inc. | Distributed analysis x-ray inspection methods and systems |
US11099294B2 (en) | 2011-09-07 | 2021-08-24 | Rapiscan Systems, Inc. | Distributed analysis x-ray inspection methods and systems |
US10302807B2 (en) | 2016-02-22 | 2019-05-28 | Rapiscan Systems, Inc. | Systems and methods for detecting threats and contraband in cargo |
US10768338B2 (en) | 2016-02-22 | 2020-09-08 | Rapiscan Systems, Inc. | Systems and methods for detecting threats and contraband in cargo |
US11287391B2 (en) | 2016-02-22 | 2022-03-29 | Rapiscan Systems, Inc. | Systems and methods for detecting threats and contraband in cargo |
US11175791B1 (en) * | 2020-09-29 | 2021-11-16 | International Business Machines Corporation | Augmented reality system for control boundary modification |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4869574A (en) | Hybrid optical correlator | |
US4645347A (en) | Three dimensional imaging device | |
US4872051A (en) | Collision avoidance alarm system | |
US3779492A (en) | Automatic target recognition system | |
US7298908B2 (en) | Method and apparatus for detecting the presence of one or more images of a known predetermined kind of scene | |
US5699149A (en) | Distance measurement apparatus for vehicle | |
US4141652A (en) | Sensor system for detecting wavefront distortion in a return beam of light | |
US4593967A (en) | 3-D active vision sensor | |
US4556986A (en) | Optical stereo video signal processor | |
US5185815A (en) | Multiple target correlator system | |
US5020111A (en) | Spatial symmetry cueing image processing method and apparatus | |
US4736247A (en) | Range and range rate system | |
US5061063A (en) | Methods and apparatus for optical product inspection | |
US4809340A (en) | Optical correlation system | |
JPH0719861A (en) | Scanning type optical range finder | |
EP0153147A2 (en) | Coherent light optical processor | |
US7368745B2 (en) | Pattern recognition system | |
EP1101146B1 (en) | High output reflective optical correlator having a folded optical axis using grayscale spatial light modulators | |
EP0612185B1 (en) | Optical scanning apparatus | |
US4958077A (en) | Method and apparatus for displaying moving objects | |
AU616640B2 (en) | Transform optical processing system | |
US6111644A (en) | Interferometer for detecting and analyzing coherent radiation | |
GB1522390A (en) | Radiation scanning system | |
US5600123A (en) | High-resolution extended field-of-view tracking apparatus and method | |
US5877855A (en) | Arrangement for the detection of targets |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: UNITED STATES OF AMERICA, THE, AS REPRESENTED BY T Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:HARTMAN, RICHARD L.;REEL/FRAME:005125/0024 Effective date: 19880504 |
|
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 4 |
|
SULP | Surcharge for late payment | ||
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 19971001 |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |